Louvet Emilie, Percipalle Piergiorgio
Department of Cell and Molecular Biology, Medical Nobel Institute, Karolinska Institutet, S-171 77 Stockholm, Sweden.
Int Rev Cell Mol Biol. 2009;272:107-47. doi: 10.1016/S1937-6448(08)01603-1.
Recent years have witnessed a new turn in the field of gene expression regulation. Actin and an ever-growing family of actin-associated proteins have been accepted as members of the nuclear crew, regulating eukaryotic gene transcription. In complex with heterogeneous nuclear ribonucleoproteins and certain myosin species, actin has been shown to be an important regulator in RNA polymerase II transcription. Furthermore, actin-based molecular motors are believed to facilitate RNA polymerase I transcription and possibly downstream events during rRNA biogenesis. Probably these findings represent the tip of the iceberg of a rapidly expanding area within the functional architecture of the cell nucleus. Further studies will contribute to clarify how actin mediates nuclear functions with a glance to cytoplasmic signalling. These discoveries have the potential to define novel regulatory networks required to control gene expression at multiple levels.
近年来，基因表达调控领域出现了新的变化。肌动蛋白以及越来越多的肌动蛋白相关蛋白家族已被视为细胞核成员，参与真核基因转录的调控。肌动蛋白与不均一核核糖核蛋白及某些肌球蛋白种类结合后，已被证明是RNA聚合酶II转录的重要调节因子。此外，基于肌动蛋白的分子马达被认为有助于RNA聚合酶I转录以及核糖体RNA生物合成过程中的下游事件。这些发现可能只是细胞核功能结构中一个迅速扩展领域的冰山一角。进一步的研究将有助于阐明肌动蛋白如何兼顾细胞质信号传导来介导细胞核功能。这些发现有可能确定在多个层面控制基因表达所需的新型调控网络。
